Whip roll controlled letoff for looms



Sept. 28, 1943. o, v. PAYNE WH'P ROLL CONTROLLED LET-OFF FOR LGOMS Filedsept. 14, 142 2 sheets-sheet 1 d 5 I F mem Ine'ntov 6 Oscar V. Payne. f

sept. 2s, 1943. Q v, PAYNE 2,330,514

WHIP'ROLL CONTROLLED LET-OFF FOR LOOMS Filed Sept. 14, 1942 l 2Sheets-Sheet 2 20 :Il o

Inventor Ganan/.Payne Patented Sept. 28, 1943 UNiTED STATES" PAT-ENTFFCE- LOOMS Oscar V. Payne, Leicester, Mass.,A assigner `to Crompton&;Kn0w1es Loom Works, Worcester; Mass.,a corporation of Massachusetts vApplication september 14,1942, sensing; 458,215 claims. (c1. 139-100)wrm ROLL CONTROLLED LE'roFFFoR vThis invention relates to improvementsin loom letoiTs and it is the general object ofthe invention to improvethe operation of that type of letoff which is controlledfby a movablewhip roll.

In my prior Patent No. 2,184,059 I have shownf a letoff mechanismemploying a Whiproll `*which is moved forwardly as warp isconsumed-against the action of a weight which'tends to move the wriproll rearwardly to tension the warp.` In that' mechanism the warp'beamisrnormally'lockedby an escapement mechanism geared to the beam yandreleased whenever thel weights reach a given height so that they Warpbeam ismomentarily released and turns to pay 01T warp Vwith anaccompanying rearward movement of the whip roll. The weights laremounted on a lever connected to a rod passing downwardly through thebrake shoe lever Which alternately locks and' releases the escapementmechanism. The rod is surrounded by a spring which presses downwardly onthe brake shoe lever and has the upper end thereof adjustable by a nutonvthe rod. In the weaving of certain fabrics it'is necessary to 'setthe adjustment for the spring within veryclose limits to prevent excessmovement of the escapement mechanism if the loom should happen'to stoponiront center when the warp 'threads'are placed under a maximum tensionIt is an important object of mypresent inven` tion to employ a fixedstop for the uppe'rendjofV the spring instead of the nut on the rodshown in the aforesaid patent, and adjust theA stopjso that it willalways cause the spring to `exerts-11i` iicient downward force to hold.the escapemc-:nt mechanism loclred regardless of variations in thevertical position` of the rod which moves with the weights.

In the mechanism shown in the aforesaid pati ent `the spring exerts anupward forcegwhich partly counteracts the downward forcev of 'theweights. The latter must therefore be relatively heavy since they mustoppose the counter-effect the `"same time attain more tensioningfoftheWar-p. 'l H- In the patented -rnechanisrn `aireadymentioned n the rodis provided; with acol-larloelow the brakel lever .and thisvl collarwill 'bey spaced `below'the brake leverwhen the `Weights aredown. As'the weights rise the spring tension dimims'hes-hut its reduced vvalue*should be -su-fiicientv to ynoldtlrebrake lever inA locking positionuntil the lever is/ posi-'tiveiy" lifted -iuy 'the coi-lari 'At thestart of upward motion of tire callan thespring is under' a 4"higherdegree 'oi compression thanv isl actually` required `forjits operationland this has been' one v factor whicnna's'made necessary Vthe use'ofheavy weights in the former mechanism. The 'stop already mentioned as apart lof rvnypresent inven-` f tion permits the setting 'of' the springso' that it exerts4 sufii'cient iorc'e to hold the brake'iever inlocking positron throughout the upwardmovement of the 'coliar with no4reduction injthat force.v Since the'downward force'of the springrremains undiminislred 'there 'is no likelihood that thebrake shoe will`sliploefor'e the collar 'engages the brake lever and the brake'canrelease the escapement mechanism'oniy 'during -tloetirire that the'collar' is' positively lifted' by the brake lever.

This 'tomey interval is pomparativeiynsnort and thespring in thepresentinstance, being under A increased compressive force. at thistime, acts promptly V'to'restore"the brake shoe to'holding po;

sition when' the weight descends. K Y

. With these andother objects in View which'will appear as thedescription ,proceedsrmyinvention resides .inthecombination"andfarran-gelnent of partshere'ina'ter describedandset'forth.

4In" the accompanying drawings. wherein a convenient embodimentfo'f -my.invention is setilor'th, Fig; 1 is a side elevation rofthe lowerrearpart of aloom showing my inventiomparts 1being in. sectionY and theweight removed yfor the Sake of deafness! ,y Y j '.3 ff..

Fig. `21s a rear elevation takenfintheyy direction Fig.' 3 is adiagrammatic :plan view in the 'directiongof arrow 3,-, 2 on ya,reducedi scale, g l Y, .FigiA l y.is a detail verticalsection throughthe spring. and rod associated therewith on lined-4,

Fia Land,

Figi-5 isa detail vertical section on line 5-5, Fig. 1, on vanenlargedscale.

' v'l'.lfie loomframe'l'fhasahraclcetfll at each sider thereof tosupport a gudgeon [.Zion' thejw'arp beam i3.v The 'gudg'eons rotatein'hearings'i111` mounted one on each lbracket li whenthe beam warp Wpasses from the warp beam barrel 2|Y to the harness frames not shown.

Each bracket |5 has pivotally mounted there-lon a lever 25 with an arm26 which extends in front of the corresponding upright arm I1.V A secondarm 21 of lever 25 extends forwardly andjv is connected to a linkdesignated generally at 28 in Fig. 3. Each lever 25 turns around apivotl stud 29 supported by the corresponding bracket I5. As shown inFig. 3 levers 25 will be acted upon by the upright arms I1 to rock saidlevers` in a counterclockwise direction about their vpivots when thewarp beam moves forwardly by a force derived from the warp, therebymoving link 28 to the left as viewed in Fig. 3.

. Link 28 has a rod head 3|! attached by an adjustable connector 3| to aweight lever 32 located at one side of the loom and pivoted as at 3 3 toa small stand 34 bolted to adjacent bracket I5. The` connector 3| ispivoted as at 35 to lever 32 ata point above the pivot33, and ahorizontal arml36 of the weight lever is provided with a series ofnotches 31 to receive a rod 33 thelower end of which carries a series ofweights 39.Y The number of weights and the point at whichtheir force isapplied4 to arm 3S may bevariedto meet different warp conditions.

Assuming that the warp beam I3 is locked against rotation, the weights39 act through lever 32, connector 3|, link 28 and levers 25 to exert arearward force on the arms |1, thereby tending to hold the whip roll 20rearwardly. As weaving continues and the warp is consumed, theV whiproll y29 will move forwardly and in doing sowill rock levers in adirection to exert apullon connector 3| to the left as viewed in Fig. 2,thereby' lifting arm to raise the weights. When` the beam is unlocked bymechanism to be described it can turn tofeed warp, at'which' time theweights descend tomove the whip roll rearwardly and maintain warptension substantially undiminished.

The locking mechanism for the warp beam includes reduction gearing andan escapement de-` vice togethervwith a lock for the latter. As shown inFig. 2 a relatively large gear 185 is `rigid with the warp' beam andmeshes with a pinion 46: fastened to a shaft 41 rotatably mounted in thevlower part of adjacent bracket Il. A Vgear 48 fast on shaft 41 andlarger thanthepinion meshes with a small pinion 49 rotating about a Astud 50 also supported by the bracket Fast with the pinion 49 is a gear5| which meshes with a small pinion 52 rotatable on anotherstud 53carried by the bracket By the gearing --just describedthe desired ratiocan be obtained between pinion 52 and the warp beam.

`By -means ofthe gearing just described pinion 52 would rotate andVpermitv gradual turning of the warp beam with loss of tension unlesssome provision were made for temporarily locking the pinion 52Vandproviding for its periodic release as required by the demands on thewarp. "This temporary locking is provided by an escapement deviceincluding a star wheel 69 fast with pinion 52 and having triangularteeth 6| the sides of which are straight and may be disposed at equalangles with respect to a radius from stud 53 passing through the pointof the tooth. I do not wish to be held to the particular shape of toothshown in Fig. 1 but have found that teeth of the shape shown thereinoperate satisfactorily.

The escapement comprises a rocking plate 19 having a hub 1| mounted on astud 12 supported by the bracket II. Secured to the plate 1B are upperand lower escapement teeth 13 and 14, re-

spectively, which rock about stud 12 and have such relation with respectto the star wheel that when the plate 1B is unlocked and rocks in onedirection, forinstance to the left, Fig. 1, the top tooth 13 will passdown into the notch between two adjacent teeth while the tooth 14 willmove out ofthe notch it previously occupied and permit the star wheel toturn. When tooth 13 reaches the bottom of its notch the inclined surfaceof the next tooth, being urged toward tooth 13V by beamgpressure, willreverse the motion of plate 10 to .permit continued turning of the sta-rwheel. 'This` will continue so long as plate 10 is unlocked and the warpbeam exerts a force on the star wheel. Each complete back and forthmotion of plate 10 permits an angular motion of the* star wheel equallto the angular distance between adjacent teeth lhand during this periodthe warp beam turns in a direction to feed warp.

In order to lock and release the escapement alternately during loomoperation the bottom of plate13 Yis provided with an arcuate rib 80having a surface 8| concentric with stud 12. A

shoe `82 faced with an anti-friction material 53` is pivoted as at `84to a lever 85 free to swing on shaft 41. Arm 86 of lever 85 extends tothe right, Fig. 1, and has extended therethrough the lower end of avertical rod 81 to which is secured an adjustable stop collar 88 underarm 8S. The lower end of a compression spring 89 pushes down on `arm |36while its upper end presses against a sleeve Silsurrounding the rod 81.The top of the rod has a head 92 pivoted on a stud 93 supported in theweight lever 32. By this latter connection the'weights 39 and the rodmove vertically together when arm 36 moves.

Thematter thus far described may be the same which is'readilyadaptableto the form of let-off mechanism shown in my p'reviouslymentioned patent.

-The escapement'mechanism is inclosed in a housing defined partly by arib |09 on the bracket and partly by a removable cover lill. In thepast. the cover has been held against the rib |00 by a .b olt threadedinto a tapped hole in the bracket Ii and this previously used tappedhole is a convenient means for holding the adjustable stop for the upperend of the spring. As shown particularly in Fig. 5 I provide an angle`stop llhaving a horizontal arm |06 formed witha slot |01 narrow enoughto pass the rod81 but not large enough torcceive the sleeve 9|).` Thevertical arm |||l` of the stop has avertical slot IlI therein whichreceives a screw ||2 tapped into a boss |3 already present on those`types of mechanisms made according to my prior pat-` ent. "Ihisi screwis'providecl` with a screwdriver asse-5114.

slot i4 and has a nut Y|15 drawn tightly against arm H to hold the stopAIllii in. vertically adjusted position against the bracket The screw isprovided with a secondnut which holds the thincasing in place. The nutcan be released for removal of the casing |.8| without disturbing thesetting of the stop |85.

The operation of the let-off mechanism set forth herein is largely -thesame as that shown in the previously mentioned patent except for theaction of spring 89 on lever 86. Previously the upper end of thespringrose and fell with the rod 81 and the downward for-ce which itexertedwas lessened as the weight arm 36 rose. In the present instance,on the other hand, the upper end of the spring is held in an adjustedbut fixed position without regard to the position of collar `88. Theparts will be set so that when collar 88 is spaced below lever 86, thespring pressure will be sucient to hold the shoe 82 against the plate l0and prevent operation of the escape mechanism. As the arm 38 rises andcollar 88 approaches lever 88 this downward pressure of the springvremains the same, and

whenk collar 88` ultimately engages lever 88 and arm 36 continues torise, lever 8B will be rocked in a ycounter-clockwise direction asviewed in Fig. l to move the brake shoe downwardly and thereby -releasethe escape mechanism. This upward motion of the right end of lever 86 asviewed in Fig. l causes an increase in the compression of spring 88 andas the escapement permits paying-off of warp and the whip roll movesrearwardly the spring will expand downwardly, and being under maximumcompression at this time, will promptly return the'brake shoe toholdin-gposition as soon as this action is permitted by descendingcollar 88. The spring will never expand, however, to a point where itwill be too weak to hold thebrake shoe tightly against the web 8B.'Thereafter the rod 8l and collar 88 can continue to move downwardlywithout eifecting the force exerted by the spring on lever 8B. A lateralfoot |28 on stop |05 engages a vertical part of rib |80 to preventturning of the stop about screw ||2 as an axis.

It will be apparent that the spring 89 as controlled by the stop setforth herein does not exert an upward force on rod 81, and the weightson arm 35 are therefore not counter-balanced in part as previously, andfor this reason a smaller amount of weight on the arm 36 may be used.When the stop is properly set to cause the spring to maintain the brakeshoe 82 in holding position the spring will always be able to exert therequired force to prevent operation of the escapement mechanism duringthat part of the upward motion of rod 81 prior to engagement of collar88 with lever 86.

From the foregoing it will be seen that IL have provided simple meansfor controlling the escape mechanism of a loom let-off by which thespring 89 exerts a downward force on lever 86 without exerting acounter-balancing upward force on lever 36. As a result of the use ofstop |05 a smaller amount of weight on lever 36 can be used thanformerly and there is no reduction in the force exerted on brake shoe 82as rod 8`| rises. Also, the maximum compressive force ever exerted onspring 89 is only slightly more than that required to hold the escapemechanism and the brake shoe 82 is subjected to a much more uniformrange of forces than heretofore.

Having thus described my invention it will be seen that changes andmodications may be madetherein by those skilled in the art withoutdeparting from the spirit .and scope of the lin-r vention and I do notwishv to be limited to the details herein disclosed, but .what I claimis:

l` .Ina letoff for a loom having a warp beam to supply warp threadswhich pass over a movably mounted whip roll the position of whichdetermines, the tension `of the warp thread, the Warp threads tending bytheir tension vto turn the warp beam, an escapement mechanism connectedto the warp beam which when `unlocked permits the warnte yturn .thebeam, e, brake to larrest the escapement mechanism .to prevent turningof` the warpY beam and movable to re-` lease the escapement mechanism, aweight operatively connected .to .the whip roll to resist movementthereof in a direction to lower warp tension,.and control mechanism forthe brake including means to move said brake to releasing position whenthe weight reaches a. given vpoint in the 'upward movement vthereoiandmeans to exert a constant force on the brake to hold the latter inarresting position withrespect to the escapement mechanism before theweight in the upward movement thereof reaches said given point. i .v

2. In a letoif `im' a loom having a warp beam to supply warp threadswhich pass overa movably mounted whip rolfl the position of whichdetermines the tension of the warp thread, the warp threads tending bytheir tension to turn thewarp beam, an esca-pement mechanism connectedto the warp Abeam which when unlocked permits the war-p toturn thebearn, a brake to arrest the escapement mechanism to prevent turning ofthe warpbeam. and movable to re.- lease the escapement mechanism, aweight operatively connected to the Iwhip roll to resist move,- mentthereof in a direction to lower warp tension, and control mechanism forthe brakeincluding a rod movable with the weightv tocause the brake tomove to releasing position relatively to the escapement mechanism whenthe weight reaches a given point in the ascent thereof, and said controlmechanism including also means to maintain constant pressure on saidbrake to hold the latter in arresting position relatively to theescapement mechanism independently of said rod before the weight in theascent thereof reaches said given point.

3. In a letoff for a loom having a warp beam to supply warp threadswhich pass over a. movably mounted whip roll the position of whichdetermines the tension of the warp thread,` the warp threads tending bytheir tension to turn the warp beam, an escapement mechanism con'-nected to the warp beam which when unlocked permits the warp to turn thebeam, a brake to arrest the escapement mechanism to prevent turning ofthe warp beam and movable to release the escapement mechanism, a weightoperatively connected to the whip roll to resist movement thereof in adirection to lower warp tension, and control mechanism for said brakeincluding a rod movable upwardly with the weight and effective to movethe brake to releasing position when the weight reaches a given point inthe ascent thereof, a spring one end vof which exerts a force on thebrake tending to hold` the latter in arresting position relatively tothe escapement mechanism, and a fixed stop for the other end of thespring.

4. In a letoi for a loom having a Warp beam to supply warp threads whichpass over a movably mounted whip roll the position of which I determinesthe tension of the warp thread, the warp threads tending by theirtension to turn the warp beam, an escapement mechanism connected to thewarp beam which when unlocked permits the warp to turn the beam, a braketo arrest the escapement mechanism to prevent turning of the warp beamand movable to release the escapement mechanism, a weight operativelyconnected to the whip'roll to resist movement thereof in a direction tolower warp tension, and control mechanism for the brake including abrake releaser movable through a given range during operation of theletoi and operative at an intermediate point in said range to move thebrake to releasing position, a spring having one end operativelyconnectedto the brake and the other end fixed, said spring normallyunder a given degree of deformation and effective to exert a constantforce on the brake to hold the latter in arresting position relativelyto the escapement mechanism before said releaser reaches said givenpoint, and said releaser after passing said point causing increaseddeformation of the spring and causing the spring to exert an increasedforce on the brake.

5. In a letoff for a loom having a warp beam to supply warp threadswhich'pass over a movably mounted whip roll the position of whichdetermines the tension of the warp thread, the warp threads tending bytheir tension to turn the warp beam, an escapement mechanism connectedto the warp beam which when unlocked permits the warp to turn the beam,a brake to arrest the escapement mechanism to prevent turning of thewarp beam and movable to release the escapement mechanism, a weightoperatively connected to the whip roll to resist movement thereof in adirection to lower warp tension, and control mechanism for said brakeincluding a rod movable upwardly with the weight, a spring normallyunder a given degree of deformation and acting on the brake tending tohold the latter in arresting position relatively to the escapemechanism, and a xed stop 5 for said spring tending to prevent movementof the latter in a direction to release the brake, said rod duringmovement thereof as the weight ascends rst'releasing the brake andthereafter increasing'the deformation of the spring to increase thetendency .of 'the latter to move the brake toward arresting positionrelatively to the escapement mechanism.

6. In a letoff for a loom having a Warp beam to supply warp threadswhich pass over a movably mounted whip roll the position of whichdetermines the tension ofthe warp thread, the warp threads tending bytheir tension to turn the warp beam, an escapement mechanism connectedto the warp beam which when unlocked permits the warp to turn the beam,a brake to arrest the escapement mechanism to prevent turning of thewarp beam and movable to release the escapement mechanism, a weightoperatively connected to the whip roll to resist movement thereof in adirection to lower Warp tension, and control mechanism for the brakeincluding a rod movable upwardly with the weight and capable during theascent thereof to move the brake to releasing position, a compressionspring surrounding the rod and having the lower end thereof engaging thebrake to hold the latter normally in arresting position, and a fixedstop for the upper end of the spring, said rod in the ascent thereofsubsequent to movement of the brake to releasing position causingincreased compression of said spring to OSCAR v. PAYNE.

